__author__ = 'East'

product_list = [
    ('iphone', 5800),
    ('Mac Pro', 9800),
    ('Bike', 800),
    ('Watch', 10600),
    ('Coffee', 31),
    ('Alex Python', 120)
]
shopping_list = []
salary = input('Input your salary: ')
if salary.isdigit():
    salary = int(salary)
    while True:
        for index, item in enumerate(product_list):
            # print(product_list.index(item), item)
            print(index, item)
        user_choice = input('选择要买的东西: ')
        if user_choice.isdigit():
            user_choice = int(user_choice)
            if user_choice < len(product_list) and user_choice >= 0:
                p_item = product_list[user_choice]
                if p_item[1] <= salary:
                    salary -= p_item[1]
                    shopping_list.append(p_item)
                    print('Added %s into shopping cart, your current balance is %s' % (p_item, salary))
                else:
                    print('您的余额只剩: %s 余额不足' % (salary))
            else:
                print('商品不存在...')
        elif user_choice == 'q':
            print('--------------shopping list-----------------')
            for p in shopping_list:
                print(p)
            print('Your current balance: ', salary)
            exit()
        else:
            print('invalid option')